Compounding the problem: Why aren’t we using the safest and most effective dispersants in the Gulf?

Richard Denison, Ph.D., is a Senior Scientist.

Imagine learning you have a serious disease. You doctor decides to treat you with a drug, noting it could have some bad side effects. He also plans to inject you with the drug, even though it’s only been used orally before now. That makes you nervous enough to ask for the name of the drug. “Sorry, I can’t tell you,” he says. “It’s proprietary.” Even if you trust your doctor, you’re now left with no way to investigate the risks and tradeoffs you’re facing.

Imagine how mad you’d be if you learned your doctor hadn’t told you there were other drugs that not only had fewer side effects, but were more effective in treating your condition. And then you learn he’s on the Board of Directors of the company that makes the drug he prescribed.

Now consider that the patient is the Gulf of Mexico, the doctor is BP, and the drug is the oil dispersants, sold by Nalco under the trade name Corexit®, more than 500,000 gallons of which have been applied to date, with no end in sight. The known side effects include short-term aquatic toxicity, but the potential for long-term effects has never been studied. Nor have the effects of injecting it into deep water, an “unprecedented” method just been approved by NOAA and EPA after hastily arranged tests conducted over the last few days. (Elizabeth Grossman has posted an excellent piece exploring the potential for adverse health effects among spill responders from both the oil and the dispersants.)

The information being withheld (in this case from the public) is the identity of the main active ingredient in the dispersants – listed only as an “organic sulfonic acid salt” on Nalco’s material safety data sheets – which comprises 10-30% of the dispersant formula. (One observer maintains the unidentified ingredient is actually described in this 2001 patent, though its composition is quite variable.)

As part of the National Oil and Hazardous Substances Pollution Contingency Plan, EPA has tested 18 different dispersants for short-term toxicity to fish and shrimp. EPA has also tested the effectiveness of surface spraying in dispersing South Louisiana crude oil. How do the two Corexit® dispersants stack up against the competition? Not very well, it turns out. They rank 13^th and 16^th in effectiveness, 15^th and 18^th in fish toxicity, and 7^th and 10^th in shrimp toxicity. At least six dispersants are both more effective and less toxic than the Corexit® dispersants.

There’s no question the ongoing spill at Deepwater Horizon is a life-threatening condition, and emergency measures are in order